Machine for finishing the heads of bolts, screws, and the like



Aug. 8, L s R K MACHINE FOR FINISHING THE HEADS OF BOLTS, SCREWS, AND THE LIKE Oi'iginal Filed June '7, 1928 3 Sheets-Sheet 1 ia A. Bard-cliff; ,peceaaeal,

Dani: EBurarz/Ff/dzbrbM/m 8, 1933. L. s. BURBANK 1,921,655

momma FOR FINISHING THE nmbs OF BOLTS, SCREWS, AND THE LIKE Original Filed June 7, 1928 3 Sheets-Sheet 2 IIIIIIII1 pm iffiurdnifjdmbzisfmfor Aug. 8, 1933. s. BURBANK MACHINE FOR FINISHING THE HEADS -OF BOLTS, SCREWS, AND THE LIKE Original Filed June 7, 1928 3 Sheets-Sheet 3 S MN Zaazls .JLBuranK Patented Aug. 8, 1933 .MACHINE FOR .FINI

BOLTS, scan Louis S. Burban Mass; by Davis E.

Worcester, Mass. ments, to The W Machine Company,

Original application June sapplication April 10,.

283,469. Divided and 1931. Serial No. 529,162

4 Claims,

The present invention relates to the manufacture of bolts, screws and the like from elongated pieces of metal, this application being adivision of the original application of said Louis S. Burbank, deceased, Serial No. 283,469, filed June '7,

In the aforesaid copending application, there is shown and described a machine for producing bolts, screws, and the like. characterized by the provisionof a series of cooperating punches and dies adapted to performa series .of developing operations upon an elongated metal blank, so that each stroke of the machine is adapted to cause a discharge of a completed blank therefrom. In the operating cycle of i this machine, the last :--p in producing the completed blank resides in operations which result in trimming and otherwise finishing the head of the blank, and the present application relates to instrumentalities for obtaining this result.

Briefly stated, the invention of the present application resides in means for operating upon the unfinished head of a blank by a pair of cooperating die and punch elements which are adapted ,to trim the head so as to impart a symmetrical form thereto an trimmed faces of the head 'as by burnishing, the above results being accomplished by an extremely simple mechanism ,eflective during one complete operative stroke of the machine. While, for purposes of illustration, the head trimming and finishing mechanism is shown associated with other parts of the machine of the original application Serial No..,283,469, obviously the mechanism of the present application can be employed separately, or in combination with other mechanisms for producing a blank with an unfinished head, all ,as will hereinafter appear, from the following description with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a machine embodying the mechanism of the present invention.

Fig. 2 is a vertical sectional view along the line 2-2 of Fig. 1, looking in the directionof the arrows and showing the parts on an enlarged scale.

Fig. 2a is a fragmentary sectional view along the line 2a-2a of Fig. 1.

Fig. 3 is 'a horizontal sectionalyiew on an enlarged scale along the line 3-3 of Fig. 2, looking inthe direction of the arrows.

Fig. 4 is a fragmentary sectional view showing on an enlarged scale the position of the parts at the start of the head trimmin g and finishing operation.

aterbury Farr Waterbury poration of Connecticut d to finish the grip arid feed a pred SHING THE HEADS or ws, AND'THE LIKE k, tdeceased, late of Worcester, Burbank, administrator,

7, 1928, Serial No. thi

(c1.- Ill-20) assignor, by mesneassignel Foundry and. Conn., a Cor- Fig. 5 is a fi'agmentaryflvie wg Similar to Fig. 4,

rimming operation par:

illustrating the head t tially performed.

Fig. 6 is a fragmentai illustrating t pleted.

Fig. '7 is a fragmentary view, similar to Fig. 6

illustrating the perform ing operation blank.

'y view, similar to Fig. 5

he head trimming operation comance of the headfini'shand theejection of the completed Like referencecharactersrefer to likeparts throughout the drawings. Referring first'to-Figsyl and 2, the invention is shown, for purposes embodied in a machine described in'the orig Serial N0. 283,469,311 chine is fully described tions thereof will'be des plication as a're nece standing .of the invention.

of illustration. asbeing of the type shown and inal' copendi'ng application d since this particular matherein, on1y such pork c'ribed in the present apssary for a complete under The machine gen erally comprises a' frame 1 which rotatably sup-' ports a shaft 2 adapted to be driven in anysuit'e able manner, as by a belt on one ofthe flywheels 3. As best shown in Fig. 2,"t-he shaft 2 provides" a centrally disposedcrank p at its free end to a he guideways 6 provided by the revolution of the shaft ciprocatory '0 head 5; 3

As best shown in'Fig.

vided therefrom by a pair of rolls are adapted to by means of a suitable dicated at 10, connec by means of a rod 11, the shaft 2 is adapte toward the head 5. in Fig.1, the wire opening 12 in the f .engagement with a knives 14 mounted movable at right an by earns 16 and 17 of predetermined le it into register with a c r back and-f cooperating die, as indicated As fully described in m plication Serial No. 283,4 shaft 2 with resulting re orti'ongi connected ad'or frame, sothat'each imparts a complete reorth'movementt'o the 1, the metal stockfrom which the blanks are made is preferably pro-i in the form of a wire 7 coiled upon'a reel 8 rotatably mounted so that wire 7 ma groovedfeedrolls 9. The I be intermittently. rotated ratcheting mechanism, inted to the driving shaft 2 so that eachrevo'lution of d to cause the rolls 9Qto etermined length of wire 7 y bedrawn "ram 5 'slidable in f foo s shown in dotted 'lines 7 is projected through an rame 1 until" it comes into" wire stop 13. Then gripping on a reciprocatory slidef15, 'gleson a shaft 18 sever ,a blank ngth from the wire and carry 1 to the line of wire feed,

ooperating punch A and V in dotted lines, y copending original apciprocatory movement of 69, rotation of thecrank' I the rear of the member 22. The punch member.

the head 5 causes a developing operation to be performed on the blank M by the cooperation of the punch Afand cooperating die following which the blank is ejected from the die. The ejected blank is thereupon seized by oscillatory transfer fingers, indicated at 19 in Fig, 1,. which fingers convey the blank into register with a second punch B and cooperating die. Each reciprocation of the head 5 is adapted to cause the punch B and its die to perform a second developing operation upon the blank, after which it is ejected so that it may be seized by a second set of transfer fingers 20 and conveyed into register with a third punch C and die C. 'The blank 7a then appears as shown in Fig. 4 with a roughly formed generally cylindrical head portion 21, and the present invention resides in the form and operation of the cooperating punch C and die C whereby one complete reciprocation of the head 5 will cause the head 21 of the blank to be.

trimmed, finished, and finally ejected from the machine.

As best shown in Figs. 4 and 5, the punch assembly designated by the reference character C comprises-a main cylindrical. punch member 22 received within an opening 23 provided in the head 5 with a pressure block 24 positioned at 22 provides a central opening 25 which receives a plunger 26 polygonal in cross section,and since the front end of the punch member 22 is beveled rearwardly, as indicated at 27, the plunger 26 is surrounded by a sharp polygonal cutting edge 28. The plunger 26 extends rearwardly into an enlargement 25a of the opening25, and a head 29 of the plunger 26 is-enga ged by a spring 30,

the pressure of which tends to yieldingly maintain the end of the plunger 26 beyond the cutting edge 28. The plunger 26 provides a central open-v ing 31 in which is received the reduced end of an ejector pin 32 passing through the spring 30. The larger end ofthe ejector pin 32 is adapted to be engaged by a lever 33 which, as best shown in Fig. 2, is pivoted at 34 upon the punch carrying head 5 with. its lower end ex-. tending below the under surface of the head 5. A spring 35 serves to maintain the intermediate portion of the lever 33 in yielding engagement with the end of the ejector pin 32, so as to maintain the opposite end of the pin within the opening 31 in the plunger 26. The lower end of the lever 33 is adapted to engage a stop 36, adjustably mounted on the frame, upon completion of return movement of the head to thereby cause the pin 32 toeject a completed blank from the punch C in a manner whichwill hereinafter appear.

Referring again to Fig. 4, the die assembly,

designated bythe reference character C, comprises a cylindrical. die member 37 providing a centralopening 37a for freely receiving a sleeve 38 having the same external form as the polygonal plunger 26. The die sleeve 38' provides a central opening 39 of such diameter as to freely receive the body portion of they blank when the blank is projected toward the die C bythe advancing punch C. The front end of the die member 37 is beveled rearwardly at 40 so that the rim of the opening 37a provides a cutting edge 41 of exactly thesame form as the cutting edge 28 of the punch member 22. The rear end of the sleeve 38 within the die opening 37a is adaptd to be engaged by a plunger 42 which, as

ially by means of a rockshaft 43 rotatably mounted within a bushing 44 carried by the frame 1. The rockshaft 43 is cut away at diametrically opposite points to provide shoulders 45 and 46 which respectively engage the plunger 42 slidably mounted in its bushing 42a, and a second plunger projects beyond the end of a bushing 50 carried by the die block 51. The projecting end of the plunger 47 is in alinement with a longitudinally movable operating rod 52 slidably mounted in the frame 1. As best shown in Fig. 2a, the rear end of the operating rod 52 projects beyond a portion 53 of the frame 1 so that, as the punch head 5 completes its forward stroke, the projecting end of the rod 52 is adapted to be struck by means of an adjustable abutment 54 carried by the head 5. Obviously, such engagement between the abutment 54 and the operating rod 52 will drive the plunger 4'7 inwardly to turn the rockshaft 43, thereby imparting movement in the opposite direction to the plunger 42 and the punch sleeve 38 for-a purpose which will shortly appear.

When the blank 7a, with its rough cylindrical head 21, is transferred into register with-the third die C and is engaged by the advancing'end of the projecting punch plunger 26, the body of the blank enters freely into the opening 39 of the die sleeve 38 until the head 21 engages the cutting edge 41 of the die member 37, thereby check-J ing the movement of the blank 7a. When this occurs, the plunger 26 yields inwardly so that the cutting edge28 of the punch member 22 engages the opposite side of the head 21 almost simultaneously with the engagement of the cutting edge 41 with the head 21. Therefore, continued movement of the punch 22 causes the head 21 to be cut from opposite sides, as indicated in Fig. 5. As the cutting edges 28 and 41 nearly meet each other, at the end of the forward movem'ent of the punch head 5, the sleeve 38 is moved quickly toward the punch member 22 by the plunger 42 through the operation of the rockshaft 43 as the rod 52 strikes the abutment 54. When this occurs, the trimmed head of the blank is forced into the opening 25 of the punch 22, the plunger 26 yielding, as indicated in Fig. 6. Theresult of this projection of'the trimmed head into the punch member 22 is that the scarf made by the cutting edge 28 of the punch member 22 passes by the scarf started by the cutting edge 41 of the die member 37, the movement of the sleeve 38 by the plunger 42 being sufficient to entirely clear the blank head from the cutting edge 41 and head and the opening 25, the punch 22 withdraws the blank entirely from the die 0', particularly as the body of the blank is freely received within the opening 39 of the sleeve 38. As the punch head reaches the end of its withdrawing movement, with the retracted plunger 26 holding the lever 33 turned back, the projecting lower end portion of the lever 33 strikes the stop 36, thereby forcing the lever 33 against the end of the pin other words, in accordance with the present invention, the trimming and burnishing or the head is carried out in what amounts to a continuous operation performed by one complete back-and-torth movement of the punch, with the burnishing being accomplished by a reversal or the direction or movement 01' the blank, simultaneously with its ejection from the machine.

What is claimed is:

1. In a machine of the class described for finishing the head 01' a blank having a shank, a pair of trimming tools consisting 01' a stationary trimming punch that receives the shank oi the blank and a reciprocating trimming punch, means to reciprocate the punch and thus cut the head of the'blank placed between said tools from opposite sides and to stop cutting before the in, to clear the blank from said die and meansto finally eject said blank from the punch and into the open space between the tools.

2. In a machine 0'1 the class described for finishing the head oi a blank having a shank, a pair of cutting tools consisting of a cutting die that receives the shank oi the blank and a cutting punch relatively movable toward and away from each other, each tool having a continuous mating cutting edge forming a circle, polygon or other shape, the innersuriace oi the punch being made approximately parallel to the movement of said tool thus giving a rubbing action to the surface passed over by the cutting edge, means to reciprocate the cutting punch for the purpose of cutting the head of a blank placed between the two cutting edges when traveling in one direction, the

punch 22, as indicated in dotted limit of said travel being such that the cutting edge of the cutting punch is spaced from the cutting edge or the cutting die, means made operative while the cutting is in progress to force that part 01' the head of the blank cut by the cutting.

punch completely into the cutting punch, means for moving the tool carrying the blank away from the other tool to clear the blank therefrom, and means to eject the blank from the carrying tool and into the open space between the tools. 3. In a machine of the class described for finishing the head of a blank having a shank, a pair of cutting tools consisting of a cutting die that receives the shank oi the blank and a cutting cutting ing having approximately parallel edges which burnish the cut surface and form a friction thereon for withdrawing the blank from the guide and means near the extreme outward stroke 01' the for forcing the blank out of the cutting punch by the ejecting plunger and into the open space between the tools. a

4. In a machine 0! the class described, for finishing the head of a blank having a shank; a pair of cutting tools relatively movable toward and away from each other, with their cutting portions facing each other and one of the pair of cutting tools receiving the shank of the blank; means to cause the tools, when the blank is placed therebetween, to cut the head of the blank simultaneously from opposite sides and to stop cutting before the opposing cutting edges meet; means away from means to move the tool therein away from the clear the shank therewith the blank supported shank receiving tool to Administrator of Lou S. ..Burba 1 k, Deceased.

purpose of cutting the head of a 

